Flotation body for hydroaircraft



4 Sheets-Sheet l Filed Nov. 29, 1922 J. P. LANGFELDER FLOTATION BODY FOR HYDROAIRQRAFT March 3l. 1925.

' 'March 31. 1925. 1,531,704

J. P. LANGFELDER FLOTATION BODY FOR HYDROAIRCRAFT Fed Nov. 29, 19122v 4 Sheets-Sheet 2 March 3l. 1925.

J. PQ LANGFELDER FLOTATIN BODY FOR HYDROAIRCRAFT 4 sheets-sheet s Filed Nov. 29, 192?,

IN VENHTOR `rc2/1H R Af/@Fama `/fITTORN J. P. LANGFELDER Y FLOTATION BODY FOR HYDROAIRCRAFT March 3l. 1925. 1,531,704

F'lmed Nov. 29, 1922 4 Sheets-Sheet 4 INVENTOR JOHNP LANQFELDEQ.

BY M JITTORNIE f Patented Mar. 31, 1925.J

UNITED STATES PATENT oFFlcl-z..y

.TOHN P. LANGFELDER, 0F JAMAICA, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CURTISS AEROPLANE AND MOTOR COMPANY, INC., OF GARDEN CITY, LONG ISLAND, NEW YORK, A CORPORATION OF NEW YORK. l

FLOTATION BODY FOR HYDROAIRCRAFT.

Application led November 29, 1922.V Serial No. 604,063.

To all whom t concern.'

Be it knownvthat I, JOHN P. LANGFELDER, a citizen of the United States, residing at Jamaica, in the county of Queens and State of New York, have invented certain new and useful Improvements in Flotation Bodies for Hydroaircraft, of which the following is a specification.

My invention relates to body construction and more particularly to flotation body construction of the pontoon type.

The invention is characterized by an allmetal body construction in which the'skeleton framework as well as the outer covering is formed wholly of metal, preferably duralumin; the disposition of the frame members and the arrangement of the cover sheets being such that ease of assembly. and accessibility are dominent factors in the design,

A further characteristic of the invention is the formation of the center line frame member or keelson in the form of a trussed beam, said keelson embodying a top chord of channel section, a bottom chord of channel section, and a plurality of chord-connecting members having their ends extended into the channels of said chords.

A still further characteristic of the in# vention is the provision of transverse formers and transverse bulkheads, the formers comprising metal strips of unbroken continuity and of channel section, and the bulkheads comprising sheet metal plates flanged marginally' to provide with the channeled formers suitable metal bearing surfaces against which the metal covering is laid and fastened. t

Other characteristics of the invention, such for instance as the Hanging of the cover sheets, the keel formation, the reinforcements obtained by crimping the metal parts, the internal bracing, etc., willl be hereinafter more fully describedy A float or body thus characterized 'is exceedingly light, exceptionally strong, and highly adapted to quantity production at minimum manufacturing cost.

In the drawings, wherein like reference characters denote like or corresponding parts Figure 1 is a side elevation of the'forward der surface is preferabl portion of the fioat or bod the outer lcovering thereof being partly roken away;

Figure 2 is a side elevation of the aft portion of the float or body;

Figurel 3 is a detail perspective View of the center portion of the keelson;

Figure 4 is a detail perspective view showing the relation between one of the transverse bulkheads, the keelson, and the outery covering of the float;

Figure 5 is an enlarged transverse vertical sectional view of the float;

Figure 6 is a detail side elevation of that portion of the interior framework of the pontoon or float into which the forward diagonal supporting strut extends;

Figure 7 is a section on the `line 7--7 of Figure 5; f

Figure Figure 5;

Figure 9 is a transverse vertical sectional view of the float showing in detail the construct-ion of one of the transverse formers;

8 is a section on the line 8-8 of Figure 10 is a fragmentary plan view of the nose portion of the oat;

Figure 11 is a longitudinal vertical sectional view of that portion of the float illustrated in Figure 10'; and

Figure 12 is a detail sectional view of claims is intended to cover anyand all types of floats.`

As shown, the pontoon, in side elevation,

is of more or less convention form. Its un- V shaped in crosssection throughout su stantially the full length of the float. Intermediately of its ends said bottom surface isprovided with a rearwardly facing step 10; that portion of said bottom surface in advancev of the step being designated as 11 and constitutin what will be hereinafter referred to as the V ydroplaning surface of the float bottom. From step ends tothe upper end of the stern.

the step forwardly the hydroplaning bottom surface 11 extends horizontally to a point well forward, from which point said bottom is inclined upwardly and forwardly t the extreme nose of the float. From the step rearwardly the bottom of the pontoon is inclined upwardly and rearwardly, such upwardly inclined bottom surface being designated as 12. The deck of the pontoon, from nose to stern,` is preferably continuously curvalinier in transverse section, the curvature, forward of the step, terminating at the chines, and aft of the step, terminating at the gunwales which (see Fig. 2) are inclined upwardly and rearwardly from the outr t the stern the pontoon terminates in a substantially vertical edge. In other words, #from the stern forwardly, the sides of the lpontoon gradually wash out to a point of merger at the step.

The framework of the pontoon, as well as the outer-covering, is constructed entirely of metal. Said framework includes as its backbone a center-line frame member or keelson designated in its entirety as 13. In its preferred embodiment the keelson comprises a top chord 14 of channel section and abottom chord 15, likewise of channel section, each channel having its open side directed inwardly. The top chord 14 of the keelson, from end to end, is unbroken in its continuity, .whereas the bottom chord 15, as distinguished from the -top chord, is broken at the step. At the step the frame sections which comprise the bottom chord 15 overla that portion of the bottom chord 15 exten ing throughout the length of the aft portion of the float being enlarged in depth at its forward end as at 16 to fit within the channel of that portion of the bottom chord forward of the step (see Fig. 3). From end to end the chords 14 and 15 of the keelson are inter-braced by vertical members 17 and diagonal brace members 18, said members being in each instance of channel section and so disposed relatively to the chords 14 and 15 as to enter the channels thereof at their opposite ends. The diagonal frame members 18 are fastened together at their points of inter-section and within the channels of the chords 14 and 15 at their opposite ends.

The top chord 14 of the keelson is laterally flanged as indicated at 19 except at the points where the chord-connecting members 17 and 18 enter the channels of the chords. At such points, the chord 14 is characterized by an absence of lateral flanges and anincreased channel depth. Such construction is conducive to maximum strength.

lThe bottom chord 15, aft of the step 10, is identical in construction. with `the top i' chord 14, though of a somewhat different Construction throughout that portion of .its

length forward of the step. The latter portion of the bottom chord 15 is laterally flanged as at 20, the flangesbeing oppositely directed and continuous from end to end throughout the full length of the forward portion of the bottom chord.l Thus organized, the flanges 20 provide the necessary flat bearing surfaces to which the bottom cover ing of the float is attached. Upon reference to either Figure 4, Figure 5, or Figure 9, it will be noted that the bottom chord 15, forward of the step, is projected beneath the hydroplaning bottom surface 11, such projected or extended portion providing a keel for the float.

At intervals of space throughout the length of the keelson 13 formers 21 and bulkheads 22 are provided, the latter being watertight, to the end that the pontoon may have a plurality of water-tight compartments. The bulkheads 22 are in each instanceof identical construction. yEach (see Fig. 4) comprises a single metal sheet having a mar- .ginal lateral flange 23 extended throughout its entire periphery. Centrally each bulkhead 22 is fastened against one of the vertical frame members 17 of the keelson as well as the top and bottom chords thereof, and at each side of the vertical center-line of the bulkhead the metal plate of which it is composed is crimped as at 24, the crimps being angularly directed symmetrically at opposite sides of said center-line to better distribute the stresses incurred in the actual use ofthe float. Preferably the crimps 24 extend angularly away from the float bottom inwardly toward the keelson.

The formers 21, unlike the4 bulkheads 22, are of framed construction. Each comprises a single length of metal strip, preferably of channel section, flattened atthe chine lines of the hull as indicated at 25 as well as at the points of intersection with the keelson. fastened to the bottom chord 15 of the keelson, i. e., to the flanges 20 thereof, `forwardly of the step, and'to the base ortion of the channel of both the top and ottom chords 15 and 16 rearwardly of said step; suvch arrangement being desirable for reasons stated hereinbefore. From. the chine lines, eachl former 21 isbraced diagonally f inwardly as at 26 to the keelson and diagonally inwardly as at 27 intermediately of the chine lines and the keel or center-line of the float. The braces 26 and 27 are also of channel sect-ion except at the ends of the braces, the'latterv being flattened as indicated. Formers thus constructed are' extremely light and exceptionally strong, and as a result of ,the singlelength of. metal strip used in their`- construction,vh the formers may be vey economically manufactured."

ollectivelythe formers 21and the bulkheads 22, togetherwith'the keelson 13, con- 130 i tical.

stitute the skeleton framework over which the outer covering for the float is laid. Said outer covering preferably comprises a plurality of metal sheets riveted together along their longitudinal abuting edges and to the frame members comprised in the pontoon skeleton. The top covering consists of two side sheets 28 and a top sheet 29, the latter being extended across the top of and upon the outside of the keelson and having its edges out-turned or flanged as indicated at 30. The side sheets 28 have flanges 31 which are out-turned to abut the flanges 30 of the top sheet 29, and along their bottom edges overlap the two sheets 32 which constitute thebottom covering. Said bottom cover sheets 32 are fastened to the flanges 2O of the bottom chord of the keelson and to the bottom edges of the side sheets 28, the fastening in the latter instance following the chine lines of the float or body.

As a reinforcement, the cover sheets 28 are crimped as at 33 longitudinally of their length and intermediate/ly of their edges,

whereas the bottom sheets 32, instead of being crimped as a reinforcement, are provided each with a crimped strip 34 fastened upon their under-surface.

The bottom cover sheets 32, unlike the sheets provided for the curved portion of the skeleton framework, are carried to the ends of the pontoon, whereas the latter terminate short of the ends, preferably in line with one of the bulkheads. The covering for the framework respectively fore and aft of the points mentioned is formed by single sheets 35 and 36, the former being conformed to the nose shape of the pontoon and the latter to the stern shape thereof.

As it is customary in pontoon construction to provide a plurality of supporting struts, provision is made within the pontoon, as an integral part of the skeleton framework, for the attachment of the lower strut ends. The struts, designated as 37 and 38, are preferably inclined to the ver- Each strut comprises side plates 39 and edge plates 40, the latter being fitted between the side plates and flanged as indicated at 41 (see Fig. 7); Over the hollow strut thus constructed suitable fairing may be placed if desired.

At the points where the strut ends enter the pontoon, inclined or diagonal transverse brace members 41 are provided, each of saidl brace members comprising a-flat metal sheet flanged in a manner similar to the bulkheads 22, though provided with lighteningholes 42. The strut ends enter the pontoon between the plates 41 and extend throughoutl the full depth thereof, terminatingv at the bottom'chord of the keelson. Preferably the plates 41 are stifl'ened through the use of diagonally disposed stifi'eners 43 arranged as indicated. The plates between strueted of some such flexible material as rubber, peripherially enlarged as at 47 and provided with an inner annular groove 48. Within the groove 48 an annular bead 49 is fitted, said bead being carried by the outer covering of the pontoon in the manner indicated in Figure 12. Hand-hole cover plates thus organized will adapt themselves in form to the exterior form of the float, and by reason of the yielding material of which they are constructed, may be easily'snapped in place to be held by the engagement between the bead 49and the annular groove 48 into which the bead is fitted.

As a further reinforcement for the float covering, channeled strips 49 may be provided to receive the abutting flanges of the Cover sheets 28 and 29. Such strips 49 (see Fig. 4) extend throughout the length of said flanges andin each instance are flattened at their terminals and directly riveted to the covering. There is also provided`interiorally of the pontoon, suitable brace means 50 in the vicinity vof that portion of the pontoon designed to withstand the catapult strains if theJmachine upon which the float is used is to `be catapulted. Moreover, for ease in towing, a tow-ring 51 may be integrally fastened at the nose end of the pontoon as indicated. Preferably the tow-ring v 51 is provided with a base casting 52 shaped to conform to the nose shape of the pontoon. Interiorally said casting 52 is provided with a center flange 53 to which the top chord of the keelson is riveted. Moreover, by reason of its disposition at the extreme nose, said casting provides also a flat bearing surface against which the bottom cover sheets are adapted to be fastened. A tow-ringl thus constructed is especially desirable in lthat the towing stresses or strains are carried and distributed throughout not only the skeleton framework of the ontoon but throughout the covering thereo as well; the latter, by reason of its rigidity,`being servzeable 'as a strength giving element of the oat. c. While I have described my invention in detail in its present preferred embodiment, it willf-"be obvious to those skilled in the art after understanding my invention, that various changes and modifications may be made therein without'departing from the spirit or scopeV thereof. I aim in the appended claims to cover all such modifications and changes.

l/Vhat I. claim is 1. In a flotation body for hydroaircraft, a skeleton framework including a metallic keel of channel section and a keelson of which said keel formsa part, portions of said keelson being extended into and fastened within the channel of said keel.

2. In a flotation body for hydroaircraft, a skeleton framework including a metallic keel of channel section and a trussed metallic keelson of which said keel forms a part, portions of the truss embodied in said keelson being extended into and fastened within the channel of said keel.

3. Ina flotation body for hydroaircraft, a skeleton framework including a trussed keelson comprising a top chord, a bottom chord, and a plurality of chord-connecting members, said chords, in each instance, being of channel section and so disposed relatively to each other as to receive in the channels thereof the ends of the chord-connecting members, and an outer covering for the skeleton framework entirely enclosing said keelson except for that portion of the bottom chord which functions also as a keel for the flotation body.

LlpIn a flotation body for hydroaircraft,

' a skeleton framework includinga trussed vide a keel for the flotation body.

keelson comprising a continuous top chord, a bottom chord having ann intermediate break in its continuity, and a plurality of chord-connecting members, said chords, in each instance, being of channel section and so disposed relatively to each other as to re- -ceive in the channels thereof the ends of the chord-connecting members, and an outer covering for the skeleton framework entirely. enclosing the top chord and that portion off the bottom chord aft of its intermediate break, said bottom chord, forward of said intermediate break, being exposed and4 eX- tended beneath said outer covering topro- 5. In a flotation body for hydroaircraft, a skeleton framework including a trussed keelson comprising a top chord, a bottom chord, and a plurality of chord-connecting\ members, said chords, in each instance, be-

ing of channel section and said bottom chord being provided with outwardly directed flanges, and an outer covering for the framework fastened to the base portion of the channel of the top chord and to the flanges of the bottom chord, said top chord being therebyentirely enclosed within saidv outer covering, whereas said bottom chord is projected therebeneath. y A.

6. In a flotation body for hydroaircraft, a skeleton lframework including a trussed keelson comprising ya top channeled chord, a bottom channeled chord and chord-connecting members having their opposite ends eX- tended into the channels of said chords, and

`'transverse formers disrtbiuted longitudinally of the length of Said keelson, the formers in each instance comprising a single metal strip of channel section throughout substantially its full length.

7. I n a flotation body for hydroaircraft, a skeleton framework including a trussed keelson, and a plurality of water-tight bulkheads distributed longitudinally throughout the length of said keelson, each bulkhead comprising a single metallic plate, crimped without being perforated, for added strength.

8. In a flotation body for hydroaircraft, a skeleton framework including a keelson and a plurality of metallic formers distributed longitudinally of its length, each former comprising a single metallic strip of channel section having its open side facing inwardly, and an outer covering for the framework fastened to the formers, the base portion of the channel of each strip offering a bearing surface against which the outer covering is laid.

9. In a flotation body for hydroaircraft, 1

lie at against the top edge of said keelson.

10. In a flotation body for hydroaircraft, a skeleton framework including-a trussed keelson comprising a top channel chord, a

bottom channel chord and a plurality of chord-connectin members engaging the channels of sai chords, and a plurality of formers distributed longitudinally throughout the length of said keelson, each former comprising a channel strip flattened at its point of contact with the top edge of said keelson and with the top edge of the bottom chord of said keelson, the formers in each .instance at their points of engagement with the top edgel of said keelson being unbrokenin continuity@ f 5111., In a flotatioxjlbody for hydroaircraft, aj'skeleton. framework including` a plurality ofy metallic, transverse bulkheads, each bulkhead being' crimped for added strength, and an outer metallic covering for the framework fastened to the bulkheads, said outer metallic covering being likewise crimped for added strength in a longitudinal direction.

12..In a flotation body for hydroaircraft,

a skeleton framework including a metallic longitudinally throughout the length of saidv keelson, each of said formers being likewise provided with flat bearing surfaces throughout their respective peripheries, and an outer covering for the framework fastened to the bearing surfaces of the keelson and of the formers.

13. In a flotation body for hydroaircraft, a skeleton framework including a plurality of transverse formers, each comprising a single length of metalstrip bent and flattened at the chines, and flattened at the keel, each strip, intermediately of said flattened portions, being of true channel section.

14. In a flotation body for hydroaircraft, a skeleton framework including a center keelson and a plurality of transverse formers distributed longitudinally throughout the length thereof, each former comprisin a single length of metal strip bent and attened at the chines and flattened at the points of intersection with the` keelson, each strip intermediately of said flattened portions being of true channel section.

15. In a flotation body for. hydroaircraft, a skeleton framework including a centrally disposed longitudinally extending vertical frame member of substantially the full depth of the float, and a plurality of transverse formers distributed longitudinally throughout the length of said frame member, each former comprising a single `length of metal strip bent and flattened at the chines of the float, flattened at the points of intersection with said vertical frame member, and of channel section intermediately of said flattened portions, that portion of each former extending across the bottom port-ion of the float being diagonally braced to Said longitudinal frame member, the braces in each instance being of channel section and provided with flattened ends which bear respectively against the formers and the frame member.

16. A hand-hole cover for enclosed bodies comprising a flexible disk adapted due to its flexibility to conform tothe exterior surface of said body together with retaining means for holding the cover disk in place.

17. A hand-hole cover for enclosed bodies comprising a rubber disk adapted to conform to the exterior surface of said body together with a snap retaining means for holding the rubber disk in place.'

18. A hand-hole cover for enclosed bodies comprising a flexible disk adapted to conform to the exterior surface of said body, and a retaining means for. the disk comprising a circular bead over which the disL is snapped. i i

19. A hand-hole cover for enclosed bodies comprising a flexible disk provided with an enlarged periphery having an annular groove formed therein together with a retaining means for said disk comprising an annular bead projecting outwardly from the body for engagement in said groove.

' In testimony whereof I hereunto affix/my' signature.

JOHN r. LANGFELDER, 

